/* Copyright (C) 2017-2019 J.F.Dockes
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published by
 *   the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this program; if not, write to the
 *   Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include "fstreewalk.h"

#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>

#include <iostream>

#include "rclinit.h"
#include "rclconfig.h"

using namespace std;

static int     op_flags;
#define OPT_MOINS 0x1
#define OPT_p	  0x2 
#define OPT_P	  0x4 
#define OPT_r     0x8
#define OPT_c     0x10
#define OPT_b     0x20
#define OPT_d     0x40
#define OPT_m     0x80
#define OPT_L     0x100
#define OPT_w     0x200
#define OPT_M     0x400
#define OPT_D     0x800
#define OPT_k     0x1000
class myCB : public FsTreeWalkerCB {
 public:
    FsTreeWalker::Status processone(const string &path, 
                                    const struct stat *st,
                                    FsTreeWalker::CbFlag flg)
    {
	if (flg == FsTreeWalker::FtwDirEnter) {
            if (op_flags & OPT_r) 
                cout << path << endl;
            else
                cout << "[Entering " << path << "]" << endl;
	} else if (flg == FsTreeWalker::FtwDirReturn) {
	    cout << "[Returning to " << path << "]" << endl;
	} else if (flg == FsTreeWalker::FtwRegular) {
	    cout << path << endl;
	}
	return FsTreeWalker::FtwOk;
    }
};

static const char *thisprog;

// Note that breadth first sorting is relatively expensive: less inode
// locality, more disk usage (and also more user memory usage, does
// not appear here). Some typical results on a real tree with 2.6
// million entries (220MB of name data)
// Recoll 1.13
// time trfstreewalk / > /data/tmp/old
// real    13m32.839s user    0m4.443s sys     0m31.128s
// 
// Recoll 1.14
// time trfstreewalk / > /data/tmp/nat;
// real    13m28.685s user    0m4.430s sys     0m31.083s
// time trfstreewalk -d / > /data/tmp/depth;
// real    13m30.051s user    0m4.140s sys     0m33.862s
// time trfstreewalk -m / > /data/tmp/mixed;
// real    14m53.245s user    0m4.244s sys     0m34.494s
// time trfstreewalk -b / > /data/tmp/breadth;
// real    17m10.585s user    0m4.532s sys     0m35.033s

static char usage [] =
"trfstreewalk [-p pattern] [-P ignpath] [-r] [-c] [-L] topdir\n"
" -r : norecurse\n"
" -c : no path canonification\n"
" -L : follow symbolic links\n"
" -b : use breadth first walk\n"
" -d : use almost depth first (dir files, then subdirs)\n"
" -m : use breadth up to 4 deep then switch to -d\n"
" -w : unset default FNM_PATHNAME when using fnmatch() to match skipped paths\n"
" -M <depth>: limit depth (works with -b/m/d)\n"
" -D : skip dotfiles\n"
"-k : like du\n"
;
static void
Usage(void)
{
    fprintf(stderr, "%s: usage:\n%s", thisprog, usage);
    exit(1);
}

int main(int argc, const char **argv)
{
    vector<string> patterns;
    vector<string> paths;
    int maxdepth = -1;

    thisprog = argv[0];
    argc--; argv++;
    while (argc > 0 && **argv == '-') {
	(*argv)++;
	if (!(**argv))
	    /* Cas du "adb - core" */
	    Usage();
	while (**argv)
	    switch (*(*argv)++) {
	    case 'b':	op_flags |= OPT_b; break;
	    case 'c':	op_flags |= OPT_c; break;
	    case 'd':	op_flags |= OPT_d; break;
	    case 'D':	op_flags |= OPT_D; break;
	    case 'k':	op_flags |= OPT_k; break;
	    case 'L':	op_flags |= OPT_L; break;
	    case 'm':	op_flags |= OPT_m; break;
	    case 'M':	op_flags |= OPT_M; if (argc < 2)  Usage();
		maxdepth = atoi(*(++argv));
		argc--; 
		goto b1;
	    case 'p':	op_flags |= OPT_p; if (argc < 2)  Usage();
		patterns.push_back(*(++argv));
		argc--; 
		goto b1;
	    case 'P':	op_flags |= OPT_P; if (argc < 2)  Usage();
		paths.push_back(*(++argv));
		argc--; 
		goto b1;
	    case 'r':	op_flags |= OPT_r; break;
	    case 'w':	op_flags |= OPT_w; break;
	    default: Usage();	break;
	    }
    b1: argc--; argv++;
    }

    if (argc != 1)
	Usage();
    string topdir = *argv++;argc--;

    if (op_flags & OPT_k) {
        int64_t bytes = fsTreeBytes(topdir);
        if (bytes < 0) {
            cerr << "fsTreeBytes failed\n";
            return 1;
        } else {
            cout << bytes / 1024 << "\t" << topdir << endl;
            return 0;
        }
    }
    
    int opt = 0;
    if (op_flags & OPT_r)
	opt |= FsTreeWalker::FtwNoRecurse;
    if (op_flags & OPT_c)
	opt |= FsTreeWalker::FtwNoCanon;
    if (op_flags & OPT_L)
	opt |= FsTreeWalker::FtwFollow;
    if (op_flags & OPT_D)
	opt |= FsTreeWalker::FtwSkipDotFiles;

    if (op_flags & OPT_b)
	opt |= FsTreeWalker::FtwTravBreadth;
    else if (op_flags & OPT_d)
	opt |= FsTreeWalker::FtwTravFilesThenDirs;
    else if (op_flags & OPT_m)
	opt |= FsTreeWalker::FtwTravBreadthThenDepth;

    string reason;
    if (!recollinit(0, 0, 0, reason)) {
	fprintf(stderr, "Init failed: %s\n", reason.c_str());
	exit(1);
    }
    if (op_flags & OPT_w) {
	FsTreeWalker::setNoFnmPathname();
    }
    FsTreeWalker walker;
    walker.setOpts(opt); 
    walker.setMaxDepth(maxdepth);
    walker.setSkippedNames(patterns);
    walker.setSkippedPaths(paths);
    myCB cb;
    walker.walk(topdir, cb);
    if (walker.getErrCnt() > 0)
	cout << walker.getReason();
}
